Checkerwork made of interlocking bricks of the same shape



June 2, WALTERS Zfilh CHECKERWORK MADE OF INTERLOCKING BRICKS OF THESAME SHAPE Filed Aug. 5. 1954 m M a.

A415 HTTQANEYS CHECKERWORK MADE OF INTERLOCKING BRICKS OF THE SAME SHAPEHarry W. Walters, Edinboro, Pa.

Application August 3, 1954, Serial No. 447,455

Claims. (Cl. 26351) This invention relates to checkerwork, andespecially to the checkers of open hearth furnaces.

As is well known, checkers absorb heat from the hot gases that leave afurnace and later on give up that heat to the incoming combustion air.An example of such checkers is shown in my Patent No. 2,519,301. In thatpatent the checkerwork is built up from bricks of two different shapes,which interlock to hold them in proper position. One shape isrectangular and the other has a rectangular body with tongues at itsopposite ends. That requires the manufacture, sale, handling and storingof two different shapes of bricks, all of which is more expensive thanif only one shape were used.

It is among the objects of this invention to provide checkerwork whichcan be formed from interlocking bricks that all have the shame shape andthat can easily be laid without confusion as to the pattern. Anotherobject is to provide checkerwork which compels the bricklayer to lay thebricks at right angles to one another, and in which the bricks will fitaccurately together and will not become dislodged from their properpositions.

Still another object of the invention is to provide checkerwork having ahigh degree or" stability against displacement and toppling by so layingbricks of a single form that each brick locks a portion of two laterallydirected bricks below it.

Another object of the invention is to provide a single simple shapewhich can readily be varied in production to produce bricks fordifferent flue sizes with only an inexpensive kind of mold change.

In accordance with this invention the checkerwork is formed from aplurality of courses of bricks in which there are horizontally spacedparallel rows of bricks crossed by like rows to form parallel verticalflues bounded by the rows. Each brick has a rectangular body that isflat or blunt at one end and is provided with a central vertical tongueat its opposite end. Each of the fluesin a course is formed from fourbricks laid in a rectangle, with each of the four having its tongueoverlapping and engaging part of the blunt end of the adjoining brick.Consequently, the tongues of bricks in a given row will fit between theblunt ends of pairs of bricks in cross rows, and the opposite ends ofeach brick become locked against lateral displacement, twisting, ortilting. Successive courses are laid so that each brick is reversed withrespect to the brick immediately below it.

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which.

Fig. 1 is a fragmentary plan view of my checkerwork; and

Fig. 2 is a fragmentary isometric view showing a plurality of courses.

Referring to the drawings, the bricks in each superposed course of thecheckerwork are laid in straight parallel rows crossed by other parallelrows of bricks. The rows are spaced apart a distance nearly the lengthof a brick and the intervening spaces form parallel vertical fiues 1with solid side walls. All of the bricks shown are the States Patent"ice same general size and shape, although they do not all need to bethe same length unless it is desired that the fines should be square.Each brick has a rectangular body 2 of standard size, and one end 3 ofthe body is blunt while the opposite end has a central vertical tongue4. The blunt end preferably is flat. Most suitably, the tongueis abouthalf the thickness of the body, but it must project from the body adistance less than half the latters thickness. Also, it is preferredthat the opposite sides of the tongue be substantially parallel and beconnected by flat shoulders 5 to the opposite sides of the body of thebrick.

Each flue that is bounded by the brick rows has the portion of it thatis in any given course formed from four bricks disposed in a rectanglewhich is square when all of the bricks have the same length. The fourbricks are laid with their tongues extending either in a clockwisedirection or a counterclockwise direction, depending on which group isbeing observed. In other words,

4 each tongue of the four bricks forming a section of a flue overlapsand engages part of the blunt end of the adjoining brick perpendicularto it, and a shoulder of the first brick abuts against the side of thesecond one. In actual practice the bricks are laid in rows, with thosein any one row laid tongue-to-tongue in pairs, whereby the adjacentpairs in the row have their blunt ends facing each other. The crossbricks have their tongues between the blunt ends of the other bricks,and the blunt ends of the cross bricks engage the sides of the tonguesof the bricks perpendicular to them. Consequently, both ends of eachbrick are held between the ends of bricks in adjoining cross rows andtherefore the first brick cannot move laterally or topple over.

As all of the bricks have the same shape, they are easy to lay and thepattern is easy to follow and cannot cause confusion to the bricklayerafter it has been started. Since all of the bricks are alike so that noselection has to be made by the bricklayer, he can lay them quickly, buthe is forced to lay them at right angles to one another. The bricks ineach course are turned end-forend relative to the courses below andabove, as indicated in Fig. 2. It will there be seen that the blunt endof each brick in the second or succeeding course rests upon a corner ofthe blunt end of each of two laterally directed bricks below it, andthereby prevents the bricks around the side of the checkerwork frombeing toppled over. All of the bricks are locked in place and cannot bedisplaced relatively to one another to form ledges that will collectdust that is carried over from the furnaces. Such dust, if allowed toaccumulate, would build up and eventually choke the flues.

Many different size bricks can be formed from the same mold or extrudedfrom the same die by merely inserting the desired filler piece in themold or die to block off a section of it. Thus flues from, for example,5 inches to 10 or 12 inches can be produced, the size of the fluecorresponding to the length of the body minus the distance between theside wall and tongue as shown in Fig. 2.

According to the provisions of the patent statutes, I have explained theprinciple of my invention and have illustrated and described what I nowconsider to represent its best embodiment. However, I desire to have itunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically illustrated anddescribed.

I claim:

1. Checkerwork comprising a plurality of brick courses in which thereare horizontally spaced parallel rows of bricks crossed by like rows toform parallel vertical fiues bounded by said rows, each brick having arectangular body with a blunt end, the opposite end of the body beingprovided with a central vertical tongue, the portion of each of saidflues in a course being formed from four bricks laid in a rectangle witheach of the four having its tongue overlapping and engaging part of theblunt end of the adjoining brick, whereby the tongues of bricks in a rowfit between the blunt ends of pairs of bricks in cross rows.

2. Checkerwork as defined in claim 1, in which each tongue is connectedby shoulders to the opposite sides of the adjoining body, and a shoulderof said overlapping brick abuts against the side of said adjoining brickadjacent its blunt end.

3. Checkerwork as defined in claim 2, in which said blunt end issubstantially flat and said shoulders are substantially perpendicular tosaid opposite sides.

4. Checkerwork as defined in claim 1, in which all of said bricks arethe same size and said fiues are square.

5. Checkerwork as defined in claim 1, in which bricks in each course areturned end-for-end relative to the bricks immediately below them,whereby the blunt end of each brick rests partially on top of the bluntends of two laterally directed bricks in the course below.

References Cited in the file of this patent UNITED STATES PATENTS429,342 Foote June 3, 1890 1,687,786 Peterson Oct. 16, 1928 2,519,301Walters Aug. 15, 1950

